Elucidating the role of a unique step-like interfacial structure of η<sub>4</sub> precipitates in Al-Zn-Mg alloy.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37267366.
- Also identified by DOI 10.1126/sciadv.adf7426 and PMC identifier 10413671.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Al-Zn-Mg alloys are widely used in the transportation industry owing to their high strength-to-weight ratio. In these alloys, the main strengthening mechanism is precipitation hardening that occurs because of the formation of nano-sized precipitates. Herein, an interfacial structure of η<sub>4</sub> precipitates, one of the main precipitates in these alloys, is revealed using aberration-corrected scanning transmission electron microscopy and first-principles calculations. These precipitates exhibit a pseudo-periodic steps and bridges. The results of this study demonstrate that the peculiar interface structure of η<sub>4</sub>/Al relieves the strain energy of η<sub>4</sub> precipitates thus stabilizing them. The atomistic role of this interfacial structure in the nucleation and growth of the precipitates is elucidated. This study paves the way for tailoring the mechanical properties of alloys by controlling their precipitation kinetics.